Vacuum-core for electrical heating devices



(No Model.)

H. R. BUTTERFIELDi VACUUM GORE FOR ELECTRICAL HEATING DEVICES. No. 447,127.

Patented Feb. 24,1891.

HIHHI IHHIIIHIIIIIHIIIHHHHHIIIHI IIIIHHIIIHHIHITTUFHTHHHHIHIHHIIIIHIHIHIIIHH UNITED STATES PATENT OFFICE.

HENRY R. BUTTERFIELD, OI IVATERVILLE, MAINE.

VACUUM-CORE FOR ELECTRlCAL HEATING DEVICES.

SPECIFICATION forming part of Letters Patent No. 447,127, dated February 24:, 1891.

Application filed June 25, 1890 Serial No. 356,653. (No model) To aZZ whom it may concern:

Be it known that I, HENRY R. BUTTERFIELD, a citizen of the United States, residing at Vaterville, in the county of Kennebec and State of Maine, have invented certain new and useful Improvements in Vacuum-Cores for Electrical Heating Devices; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

Ileretofore resistance-coils forming part of an electric circuit have been employed for generating heat in radiators, cookers, fryingpans, flat-irons, and other electric heating devices, the coil or equivalent resistance being commonly located within the hollow shell of the heater or inclosed in a recess thereof, but always in contact with the air, and thereby liable to oxidation and the possibility of leakage. To obviate these defects I make use of a removable hollow shell, which is exhausted of air and contains the resistance, the latter being, therefore, in mono. This core and contents are received within the calorific device or article, or some hollow part thereof, and heated by the passage of the electric current.

I11 the accompanying drawings, Figure 1 represents a side elevation, partly broken away, of a tailors goose provided with my improved vacuum-core and resistance as a means of heating it. Fig. 2 represents in perspective the core and its tray detached. Fig. 3 represents a similar view of said core with the side partly broken away, and Fig. at represents an enlarged longitudinal sect-ion of said hollow core, the middle parthein g broken away.

A designates the hollow body or shell, and A the handle of atailors goose,which I have selected to illustrate my invention, although any other heating or heat-applying article or structure would answer as well.

13 designates aremovable flat plate or tray, which slips endwise into and out of said shell, and has secured on it a hollow cylindrical core 0, inclosiug a vacuum. To allow the production of the latter, said core is provided at one end with a steam-inlet pipe 0 and at the other end with an air-outlet opening 0' and a wateuoutlet cook 0 There is also a transverse partition I, which cuts oil the ex tremity of the interior of said core, forming a chamber J, and provided with an opening a in line with 0'. Both these openings are screw-tapped and receive the same screwplug 0 The steam-inlet pipe 0 is similarly screwed into an opening of said core and may be so turned therein byhand or any convenient implement as to cut off the steam.

To produce a vacuum the steam is first let in through said inlet and the plug 0 removed to allow the expulsion of the air. The steaminlet pipe 0 is then turned to cut off the supply of steam. The plug 0 is screwed back to close opening 0, but not opening i. The core is cooled to reduce the steam to water and turned until the water runs into the space J. The screw-plug c is screwed into partition I, closing opening tand bottling the water in said space. The water-outlet cock is opened and the water allowed to run oil through the same, then closed again, and the vacuum is for practical purposes complete. Even if air should enter through said cock as the last of the water escapes, it cannot pass the partition I. \Vithin this vacuum a resistance-coil D is wound spirally, as shown, or arranged in any other convenient way, its ends being by preference near each other atone end of said core, and held by binding-posts G G, which also hold the circuit-wires II II. The ends of the core G are provided with journals K, which are supported in bearing-standards I raised on tray B, allowing said core to be turned on its longitudinal axis in order that the water may run through opening into space J, and again, after another turning from this latterspace, throughthe water-outletcock.

I do not confine myself to any particular shape of core or arrangement and construction of resistance, although I prefer those which Ihave shown and described. Instead of placing the resistance in avacuum I may fill the interior of the hollow core with any non-combustible gas which is incapable of acting chemically on the resistance; but a vacuum is better.

I am of course aware that electric lamps are often provided with resistances inclosed in mono to produce light without appreciable combustion; also, that this has sometimes IOO been done for the supplemental purpose of regulating the light. These are notcalorilic devices, and I do not claim them. I

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In an electric heater, a hollow core inclosing a vacuum and a resistance which forms part of an electric circuit, thesaid core being provided at one end with a partition cutting 01? a space J, a screw-plug closing at will air-outletsin thesaid partition and the end wall of said core, or the latter only,a wateroutlet cock from said space, and a steam-inlet into the body of the core, substantially as set forth.

2. In combination with the shell of an electric heater, a. hollow core inclosing a resistance which forms part of a circuit and having journals on its ends, and a removable tray or plateprovided with bearing standards In testimony whereof I affix my signature in presence of two witnesses.

HENRY R. BUTTERFIELD.

Witnesses:

WARREN O. PHILBROOK, FRANK L. PLU ER. 

